Various embodiments of a seat track assembly are described herein. In particular, the embodiments described herein relate to an improved positively engaged locking (PEL) mechanism for a vehicle.
Vehicles commonly include seats that are movably mounted on a vehicle floor to provide an adjustable position of the seat relative to the vehicle floor in fore and aft directions. For example, the occupant of the driver's seat may want to adjust his or her position relative to the steering wheel, brake, and accelerator pedals. The vehicle seat may be mounted on tracks for slidably moving the seat in the fore and aft directions along the vehicle floor. Commonly, a pair of track assemblies is mounted between the vehicle floor and the seat bottom. One track assembly is generally mounted on the inboard side of the seat, and the other track assembly is generally mounted on the outboard side of the seat. A typical track assembly includes a lower track bolted to the vehicle floor. An upper track is mounted on the seat. The upper track is slidably mounted on the lower track. Ball or roller bearings are commonly provided between portions of the tracks for ease of moving the upper track relative to the lower track.
Seat track assemblies may include a locking assembly that prevents the tracks from moving relative to one another during normal use of the seat. When the user wants to move the seat position, the user actuates the locking assembly to an unlatched position, thereby permitting the seat to be moved to a desired position. After the seat is in its desired position, the user then moves the locking assembly to a latched position, thereby preventing the seat from moving relative to the floor.
Known locking assemblies include one or more locking pins that move substantially vertically or substantially horizontally relative to the seat track assembly. U.S. Pat. Nos. 6,874,747 and 7,191,995 illustrate examples of known track assemblies. The track assemblies include locking pins that move substantially horizontally into and out of openings formed in the tracks between locked and unlocked positions. U.S. Pat. No. 6,637,712 illustrates an example of a known track assembly that uses pins slidably mounted in a vertical orientation, wherein the pins extend underneath the tracks when in their locked position. U.S. Pat. No. 7,207,541 discloses a seat track locking device with pins 40 having a circumferential groove 50. The pins 40 extend into bores 38 having annular projections 54. During a crash, the pins 40 bend at the groove 50 and the projections 54 bend radially outwardly. The grooves 50 of the pins 40 engage the bent projections 54 of the bores 38, thus preventing the pins 40 from bouncing upwardly and out of the locked position.
The above notwithstanding, there remains a need for an improved seat track assembly that prevents the tracks from moving relative to one another during normal use of the seat and during an impact or crash event.